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Marshal.FinalReleaseComObject Method

Releases all references to a runtime callable wrapper (RCW) by setting the reference count of the supplied RCW to 0.

Namespace:  System.Runtime.InteropServices
Assembly:  mscorlib (in mscorlib.dll)

[SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
public static int FinalReleaseComObject(
	Object o


Type: System.Object

The RCW to be released.

Return Value

Type: System.Int32
The new value of the reference count of the RCW associated with the oparameter, which is zero if the release is successful.


o is not a valid COM object.


o is null.

The FinalReleaseComObject method releases the managed reference to a COM object. Calling this method is equivalent to calling the ReleaseComObject method in a loop until it returns 0.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0